FAQ

• Search this page only using Ctrl+F for windows.
• Search the entire User Manual with the excellent Docuwiki “Search” feature in the upper right title bar.

• Not covered in the User Manual which I have already studied and searched.
• Search OpenCPN Forum on Cruiser's Forum[45] by using the Search Dropdown on the right hand side for “Posts” or Threads“.

opencpn:manual:cruiserforumsearch.jpg

1. In the editing window, use the paper clip
2. Or hit Go Advanced at the bottom, then under Additional Options select Manage Attachments
3. A pop-up window will appear.
4. Select your screenshot
5. upload it (if you don't see “upload”, scroll right)

Attachments from “newcomers” are often landing in quarantine, and are reviewed by the moderators, so please be patient.

There are some size restrictions on various types of documents which will prevent upload (scroll down the upload file screen for more details. If your file is larger than these restrictions, rename them as noted below. For large zipped, txt or doc files we will often rename them in this way:

• verylargeword.doc —> word.doc.pdf
• verylargetext.txt —> verylargetxt.txt.pdf
• largezipfile.zip —> largezipfile.zip.pdf

PDF size is larger, so we often use that. Then we note in the post to remove the ”.pdf“ after download.

Read this explanation - Getting Started[46]

Read this explanation - Getting Started[47]

It is downloaded with the software, so use “?” icon and then “Help”! It is also available on the Website Download page[48] Then scroll to the bottom under ARCHIVES.

A big contributing factor to this problem is that Windows default settings hides system files, and also by default, don't show file extensions.

1. These settings can be changed however.
2. In XP go to My Computer →Tools → Folder Options -View. Mark “Show hidden files and folders” and uncheck “Hide extensions for known file types”.
3. Other versions of Windows are similar, but may not be exactly like this.

Now you should find the files we talked about in the previous paragraph.

Keeping an updated list of all the devices available is virtually impossible.

1. As long as your device is able to produce NMEA 0183, OpenCPN most likely won't have any problem understanding it.
2. Rather than looking for a list, which can't contain everything, ask in the support forum whether your equipment of choice is likely to work with OpenCPN before going shopping.
3. If still looking for lists, you may like the following links
   1. Information about connecting various devices to OpenCPN:Supplementary hardware[49]
   2. Radars for OpenCPN: Radar Overlay[50]

• Yes. Simple Setup. The USB Hub with the device drivers creates a separate Virtual COM port for each USB at the required speed. OpenCPN then acts as the Multiplexer when you make separate Connections for each of the virtual COM ports created. Example:
• Inateck USB3.0 3-port hub with gigabit ethernet port $20
• Bu-353-S4 GPS puck[51] $25
• dAISy AIS Receiver[52] $70
• Tiny Seatalk Link[53] $150 for Raymarine Instruments (up to ST60).
• Label the ports for the devices and use those ports or you'll be redoing OpenCPN “Connections”.
• Install each device's drivers.
• or another example, Vesper AIS and RS422 NEMA instruments.
• For more about Supplementary Hardware[54] or consult with a marine electronics service.
• A multiplexer will join multiple sources into a single output to OpenCPN. Multiplexers come in a great variety, to do many different jobs, read the specs.
• Tips for working with multiple serial sources
  • Label the hub and usb devices and always plug them into the same location once they work in Opencpn.
  • OCPN will never assign a port to a new connection by itself, you must select one from the dropdown list OR enter it yourself, for example: “COM11”.
  • To confirm which COM port is used for a USB device, open Windows Device Manager and watch what happens when the device is connected and disconnected from the USB-HUB/Splitter.
  • Then select or enter the corresponding COM port in OCPN Connections.
  • Be sure to set correct baud rate.
  • To find and use the Device Manager look here[55]

• You can add absolutely anything to the filter (Click on the “Add” button), the predefined list is there just to save you some typing for the most common message types.

• OpenCPN runs with many OS including Android, Linux (many flavors), Windows & MacOS.
• OpenCPN will never work directly with iphone because the iphone store limits production of a version of OpenCPN.
• OpenCPN can be used on an iphone with VNC.
  • Use a small Linux computer like Raspberry Pi 3 running Openplotter.
  • Then use a VNC viewer in full screen mode on an iPhone or iPad to view the RPi screen over Wi-Fi.
  • Put OpenCPN on the RPi and you effectively have OpenCPN on an iThing.
  • You can get the RPi for <$50 US.
  • Screenshot of VNC with an iPad or iPhone
  • 

1. OpenCPN Installation[56]
2. Chart Files Tab[57]
3. Installing Charts with Chart Downloader Plugin Chart Downloader[58]
4. Installing GPS GPS Setup and Status[59]
5. Instruments - Devices must provide NMEA 0183 data via Serial or Network with a range of protocols and settings available. The description for connecting to hardware is in the Options > Data Connections section. Connections[60] and for additional assistance NMEA Sentences[61]
6. See Supplementary Hardware[62]
7. Also read Supplementary Software[63] which has information about using an Android Phone's GPS[64], etc.

If the screen view is not in a place where charts are located then it will not show any chart keys. Try zooming out until piano keys show up.

On Rpi I type Telnet localhost 10110 I see the stream of NMEA 0183 sentences coming from the Signalk Server. Apparently OpenCpn does not work that way.

OpenCPN does not recognize anything other than Q4 notation in the address field. “localhost” is a semi-standard shorthand notation, used on many systems and apps. In OpenCPN, Instead of “localhost”, use ip of 127.0.0.1. It is the same thing.

1. It is highly unlikely that uninstalling and reinstalling OpenCPN is going to resolve anything, really. But if you can't resist the temptation, help yourself, it is equally unlikely that it makes the things worse.
2. You should have a look into the logfile to find out whether it contains some clues that could help isolate the problem. If the crash is related to displaying a chart, try to isolate on which one and create the simplest possible scenario we could reproduce. You should try to get fresh charts.
3. You should try disabling OpenGL if it is enabled or vice versa.
4. While OpenCPN is not running, move the complete data folder (C:\ProgramData\opencpn on Windows, ~/.opencpn on Linux ~/Library/Preferences/opencpn / on Mac ) to a backup location and see whether something was rotten in your local OpenCPN data. Do not delete it if you want to keep your waypoints, routes and tracks!
5. If on Linux, run opencpn from command line and see whether it produces a backtrace to help identify the cause of the crash.
6. Still on Linux, you can use gdb or another debugger to get the backtrace and help identify the cause of the crash.

1. Look in the opencpn.log file. Try closing Opencpn, deleting the opencpn.log file and then reopening OpenCPN to create a new log file, then use Opencpn to cause the trouble again. Then look at the Log file to find messages that are associated with the problem.
2. Verify the problem is not from an old and outdated opencpn.ini file. Rename your opencpn.ini file for possible reuse later, and restart Opencpn to create a fresh new opencpn.ini file. Test for the problem.
3. Do you have Chart Display problems? Try turning on or off OpenGL and Running update of the Chart Database.
4. Do you have a problem with paid charts? see Oesenc or ocharts.
5. Do you have old plugins? Disable and uninstall all external plugins with the plugin uninstall program. Test OpenCPN and then download new updated plugins and install them one at a time and test.
6. Final Resort: Try starting over by uninstalling Opencpn following this approach.
   • Go to the ProgramFiles “OpenCPN” folder, and use the uninstall programs, preferably starting with the plugins, and ending with the OpenCPN.
   • Check that the “opencpn” initialization folder of program data has been removed. Otherwise, do it manually.
   • Use the CCleaner software to clean the PC Windows registry in particular. (option)
   • Download OpenCPN again and all the plugins you need.
   • Install OpenCPN.
   • Run OpenCPN to verify that the operation is correct.
   • Install, one by one, the plugins you need.
   • Run each plugin before installing another one

- Try this approach instead - Troubleshoot Installation[65]

When you “Navigate to” a waypoint from OpenCPN, he does the following:

1. Create a temporary route from current position to selected point. The route has only two points, start and end.
2. Activate that route.
3. If a suitable output connection is available, he sends the following NMEA messages periodically to that port.
   • ECRMB
   • ECRMC
   • ECAPB
   • ECXTE
4. The Cross-track error (XTE) output by OCPN is calculated as for Rhumb Line Sailing, i.e. straight line on Mercator chart.

If an autopilot is steering the boat, it may choose to follow GC route if it wants to. The current GPS position and the target waypoint position are available in the messages sent above.

If the A/P uses only XTE, then it is sailing Rhumb Line. Alternatively, if it ignores XTE, and computes a running GC course based on the target waypoint location and current ownship position, then it is doing GC Sailing.

If the A/P is doing GC Sailing, then you would see the XTE reported by OpenCPN diverging from zero, as expected.

Of course, other chart plotters may do this differently from OpenCPN.

Personally, I wonder why we care. Rare indeed would be the case in which a two-point route long enough to benefit from GC Sailing would be traveled without need to change course for other tactical reasons (weather, traffic, etc.). Could happen with a large motor vessel, I suppose…

Users generally prefer rhumb line because

• Course does not keep changing.
• A route on any normal paper chart is a rhumb line. If my plotter uses the same rhumb lines everything matches, such as XTE, courses and distances.

• See Getting Started > GPS Setup[66]
• But I know my GPS is working because the GPS program shows that it is working fine. Have you closed that program before trying to connect OpenCPN to the GPS? Only one program can connect to the GPS at a time.

If you can “see” your position in the Win10 GPS Program, OCPN would also find it if you:

1. Disconnect the GPS Device from any program using the assigned Com port.
2. Connect OCPN to the same Com port using the correct baud rate.

See OCPN wiki how to find what Com port to use[67]

• Make sure you have downloaded the latest drivers. For BU-353-S4 use USGlobalsat Corporate[68]
• Older Globalstar models (before BU-353-S4) don't work well with Windows after W7.
• Always plug the Puck into the same usb port. (Label your USB Hub ports with each USB device to be connected.) This is not a requirement but it makes the connections more reliable and trouble free without having to change Opencpn settings each time.
• Another approach for Windows Users:
  • When the GPS is inserted into a USB port, the comuter assigns a COM port number to that device. Go to Device Manager and look for the line Ports (COM & LPT). Click on the > to the left of this line. The newly installed device will be listed. In the case of many GPS units the driver will be listed as 'Prolific USB-to-Serial Comm Port (COMX)', where 'X' is the number that has been assigned by the computer to that USB port for that device.
  • If you now insert the GPS into another USB port you will find the computer assigns a different number to the GPS.
  • To setup your computer for maximum convenience in being able to insert the GPS into any USB port and have the same COM port number (making OpenCPN happy) you can change all USB ports to have the same COM port number for the GPS.
  • Procedure: Right-click on the line “Prolific ….”. Left-click on 'Properties'. Open the tab 'Port Settings'. Click on the button 'Advanced'. Click on the elevator button. Scroll to the COM port number you want to use for the GPS in all USB ports and click on it. (I use COM1) Click on 'OK' twice. The COM port number you selected appears in the 'Prolific … ' line. (Older versions of Windows requires refreshing)
  • But only this USB port has been changed. To make other ports the same remove the GPS and plug it into another port. If you left the Device Manager page showing you will see the 'Ports (COM&LPT) line disappear and re-appear. The 'Prolific …' line will show another COM port number. Follow the procedure above to select the same number you first used. This time when you display the list of COM ports your target COM port will show '(in use)' after it. Disregard and select it. Click on 'OK'. This brings up an error window 'Communications Port Properties' advising the selected COM port number is being used by another device etc. Click on 'Yes'. When the windows clears click on 'OK'.
  • Repeat the above for the rest of the USB ports. Now it doesn't matter which port you happen to use for the GPS the assigned COM port number is the same.
  • Now go to OpenCPN and select your common port number under Options/Connections.

1. OpenCPN Installation[69]
2. Perhaps you'd like to download some charts? We suggest using Chart Downloader[70].

1. OpenCPN used to display charts with an unknown projection as a Mercator chart. The same thing applies to an “UNKNOWN” or not recognized geodetic datum, where OpenCPN used to default to WGS84.
2. This is no longer the case. If OpenCPN don't recognize the chart projection, it will not be displayed.
   • Potentially serious errors are thus avoided.
   • The event is logged in the opencpn.log.
   • Users may run into problems if a chart projection is stated as “UNKNOWN” even though it really is a prefect Mercator chart.
3. Unfortunately, some conversion tools take a shortcut and don't enter the “PR” tag in the kap-chart-header correctly.
   • The projection of a chart can always be found, and the “PR=UNKNOWN” should always be avoided.

Official charts that OpenCPN really can't display, with a latitude < 70 degrees north/south, are very few indeed. Really only a handful of legacy, Gnomonic, large scale charts. Charts with “UNKNOWN” or blank geodetic datum are best avoided, they may be dangerously inaccurate.

Messages like:

• ”ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.side ALSA lib audio/pcm_bluetooth.c:1614:(audioservice_expect) BT_GET_CAPABILITIES failed : Input/output error(5)“ or
• ”(opencpn:8979): Gdk-CRITICAL : IA_gdk_drawable_get_size: assertion `GDK_IS_DRAWABLE (drawable)' failed“
• '(opencpn:8979): Gdk-CRITICAL : IA_gdk_drawable_get_depth: assertion `GDK_IS_DRAWABLE (drawable)' failed Error opening coefficient file”
• “(opencpn:8979): Gdk-CRITICAL : IA_gdk_window_get_origin: assertion `GDK_IS_WINDOW (window)' failed”

are quite normal and have nothing to do with OpenCPN. Just ignore them!

Apparently sometimes Toobar works and sometimes not. When the toolbar is not visible, the problem is that ocpnToolbarDialog was created with very small dimensions. See Github Issue #820[71] for how to edit the config file.

1. See Plugin API Versions[72]
2. It is best to keep OpenCPN and plugins updated to the most current version.
3. If you are having trouble, it is likely you will be asked to update plugins and Opencpn to be current.

1. There are two versions in the Google Play Store. We suggest you will be happiest with the paid version created by D. Register because it is updated regularly and is current. There is a forum at http://bigdumboat.com/aocpn/forum/[73].

1. The behavior you see is expected for ENC charts. ENCs must be converted to internal SENC format before use for navigation. This takes a little bit of time, depending on your system capabilities. But it only has to be done once, and the converted SENCs are stored on your system for later use.
2. All ECS systems must convert ENCs to SENCs. Some take longer, (like OpenCPN), so that subsequent access is faster. Some convert faster, leaving more work to do at the time of actual chart display. Its a design decision. OpenCPN is optimized for speed in real use, not for speed in conversion.

1. If I turn off quilting, I can select the individual maps just fine and zoom to any level on them. No amount of clicking/hiding the maps using the map bar at the bottom of the screen show the maps. Only a zoom allows them to be seen. This problem of disappearing maps happens all over the country at different zoom levels.
2. Answer: OpenGL is turned off. Without OpenGL, OpenCPN will not quilt Mercator and Transverse Mercator charts together. Try enabling OpenGL with Options (wrench tool icon)> Display> Advanced. Click on the box between “Graphics” and “Use Accelerated Graphics (OpenGL)” to put a checkmark in the box.
3. When OpenGL is enabled, OpenCPN will quilt Mercator and Transverse Mercator charts (and some other projections).
4. If “Texture Compression with Caching” is enabled under “OpenGL Options” there will be a delay before each chart is displayed for the first time. Subsequent display of the charts in the cache will be faster.

• Chances are the chart file is corrupted.
• Note the name and number of the suspect chart and replace it with a fresh download.
• Read the log file that may contain relevant information regarding the chart.
• Sometimes the bad chart blocks OpenCPN from restarting.
• Follow these instructions instead Troubleshoot Installation[74]

Most users just want to get rid of the triangles, but please refer to the Quality of Data[75] Documentation.

1. In Options > Charts > Vector Charts Tab when using Display Category “All”, Uncheck “Chart Information Objects” which hides the “U” symbols .
2. In Options > Charts > Vector Charts Tab for a finer grain control when using Display Category “Users Standard”, In the selection List Box, Uncheck “Quality of Data” which hides the “U” symbols.
3. If Quality of Data is checked, then the Shortcut Key “U” should toggle the “U” symbols on and off. See Keyboard Shortcut[76]

Also, when viewing ENC charts:

1. “U's” show up all over the charts
2. Text detail seems to be missing ..like buoy identification ..Bridge names and clearances etc…
3. Depth sounding seem to disappear zooming in and out.

Hit Text: The A+ button. To show text.

This isolated danger symbology is a part of the new ENC S57 presentation standard which OpenCPN complies with, get used to it. OR You can try to cover them with your depth setting. Look at the manual Vector Display Tab > Shallow, Safety & Deep Depths[77] Safety Contour“, where you will find an example of just how depth is taken into account when displaying the magenta cross.

• Safety Depth = 2 meters almost of the pink crosses are covered, but not those in depths 2-5m.
• Safety Depth = 10 meters all pink crosses are covered and you have lost your pink friends.

Chart text can quickly be hidden/shown by the key “T” but be sure to have correct text options checked, see below. Alternatively click on the “A+” Icon in the toolbar. If still no joy, make sure you do not have the texts disabled in the configuration Options > Charts > Vector Display Tab[78]. Also see Chart Text Settings[79].

Lights and Anchoring Info always start up activated, whereas Text and Soundings state is remembered. This is intentional. If there is no text or no soundings you will notice there is something missing. For lights and anchor it is not always easy to be aware if it is on or off, so for safety the default is on. If you like a default off, use “Users Standard” and switch the lights and seabad features off (but this is not a recommended state). See Keyboard Shortcut[80]

The Charts American ENC NOAA charts. The chart advises OpenCPN what symbols to be used and where to put them. Inspecting the chart usually yields the answer. For example At blake island the entry to the marina is coded as ObjectClass:

Beacon, lateral
Acronym: BCNLAT
Where as
Buoy, lateral
Acronym: BOYLAT

This is the common way for a chartmaker to code the chart.

Also at Blake island the topmarks are coded as

Daymark
Acronym: DAYMAR
while the common way is:
Topmark
Acronym: TOPMAR

What you see is the way the chartmaker intended it, or the chartmaker was an apprentice wo messed things up.

Answer: Using Options → Charts → Vector Charts this is the correct display when using “Simplified” chart feature display. If you switch to “Paper Chart” feature display, you will see the more familiar images for the topmarks.

1. The black regions never seem to go away, but change the Vector Chert Setting, “Boundaries” from “Symbolized” to “Plain” and the problem is resolved. These may be hatched/plain areas when changing the settings, or perhaps some national water delimitation is drawn plain or fine-dashed (Gibraltar).

1. Try using the “V” shortcut key which shows/hides Hides/shows all navobjects. The only exceptions being the active route and track which are always drawn on the chart canvas.

1. Old versions of OpenCPN were correcting broken KAPs on the fly. (They work on 3.2 but not on any 4. release ) The new ones don't do it anymore as the number of damaged charts circulating around decreased significantly and we gained some extra performance during chart loading. Refer to these sections of the User Documentation too.
2. Chart Conversion Manual[81] Specifically libBSB and ImgKap and Kap files.
3. To fix your charts, run bdbfix on them.

1. Condition: Multitude of repeated waypoints, which get copied when a waypoint is dragged. Sometimes a route WP is shifted, two routes are made, one with the name, the other unnamed.
2. Possible Solutions: Determine if the addition of waypoints are from inadvertently hitting the wrong keys on the keyboard, or the mouse.
3. The other possiblity is that the navobj change file is corrupted. Close O and try to delete the change file In W8.1 it is found in C:\ProgramData\opencpn/navobj.xml.changes. Normally, after that O will work again.

One possibility is that you have the space-bar set to drop a wpt at the boats position. This used to be standard behavior some time ago. If this is a problem, shut down OpenCPN. Open the file opencpn.ini, find the line:

 SpaceDropMark=1  and change it to   SpaceDropMark=0 

Save and restart O.

• Go to the Toolbox and enable “Zoom to Cursor” on the Display→General tab

See Use-seaclear-wci-charts[82] and Oziexplorer to Opencpn[83] Also see Not supported formats that can be converted[84] and Map2Kap and WCI Charts

• Yes. I had originally created and maintained all my routes and waypoints in SeaClear, exported them, loaded them into GPS Utility (for Windows) and saved them as text files.
• To import into OpenCPN I opened all my text files (routes and waypoints) with GPSUtility, saved that out as one big gpx file, and loaded it into OpenCPN. Works like a champ.
• I've edited them and saved them back out as GPX files with no trouble.
• Individual routes can be edited and saved in appropriately named GPX files.

No, not directly, they are in different formats. But you can convert them with the GPS Utility Program. Here's an older writeup Conversion of MaxSea Routes and Tracks[85] Use an external tool to convert the proprietary Maxsea data to the open GPX format. Either the free C2GPXKML[86] or shareware GPSUtility[87] could help. Also if you have access to Maxsea, export all waypoints as Gpx and OpenCPN will read the gpx file. If different color waypoints is used, export them separately and and in a text editor change icon name to an icon used in OpenCPN.

Three ways to synchronize:

• From the Route & Mark Manager > Route Tab, select “Export all visible” or highlight select routes and “Export Selected” to a gpx folder. Then use saved gpx file to import the Routes to another computer. For Marks pick the Waypoint Tab, select “Export all visible” or highlight select waypoints and “Export selected” to a gpx folder. Then import waypoints from the other computer.
• Copy the navobj.xml file to the second computer's navobj.xml file, which will overwrite your routes and marks on that computer. If you are connected via a network you can make a batch file to do this.
• To copy all waypoints or routes, make a copy & rename the navobject.xml file to .gpx file and import the waypoints, routes and/or tracks. This does all waypoints/routes/tracks at once.

The navobj.xml file resides in the same folder as the opencpn.ini settings file, under the OpenCPN User folder. For windows this is usually “C:\programdata\opencpn\”. The navobject.xml file is in in fact a .gpx file containing all waypoints/routes/tracks. See Navigation Data Backup[88] for more information.

Make a script or batch file to copy to navobject.xml file. Make an icon for the batch file on your desktop. Examples: Make an icon for the batch file on your desktop.

Copy-Routes-AB.bat

Copy \\ComputerA-name\C:\ProgramData\opencpn\navobj.xml \\ComputerB-name\C:\ProgramData\opencpn\navobj.xml

Copy-Routes-BA.bat

Copy \\ComputerB-name\C:\ProgramData\opencpn\navobj.xml \\ComputerA-name\C:\ProgramData\opencpn\navobj.xml

For more discussion see Cruiser Forum Thread Real-time sharing waypoints and routes[89]

If you did delete the original [route, wpt, track], you may still have an automatic backup in an older navobj.xml.[1-5] file. Don't restart Opencpn again, until you retrieve the data you want. See Navigation Data Backup[90] for more information.

This problem has been traced to shutdown management. Please see Tracker FS#2245[91] and OpenCPN and Linux powerup/down management[92] For Windows and MAC users it is suggested that it is best to shutdown OpenCPN first, then shutdown the Computer.

• Export the waypoints to a file and open this file in a text editer (Notepad?)
• Do a search and replace on the ScaleMinvalue (Default = 2147483646) to anything you like.
• Save the file and import again in OpenCPN.
• This way it doesn't take two days but just over two minutes instead

This depends on what “a bit ago” actually is - (if you have since started OpenCPN more than 5 times, every time did some change to the navigation objects and did not change the default settings for backups, you don't have it anymore) - If you do not have that backup anymore, you may still export the route as GPX file which you may later edit in a text editor and make a track again (But you already have lost some precision as during the conversion to route the points recorded in the original track are interpolated to limit their total number) - Later: your track seems to still be there as the yellow highlight it has seems to be visible, so you should be good just deleting the route.

Deleted all routes in the Route & Mark Manager. Found a gpx Route File folder under documents on my computer. Importing all gpx routes into Route & Mark Manager from Route folder by highlighting all the routes. Now multiple routes with the same name show. How can I correct this. Importing a route at a time is tedious.

I had previously exported all visible routes and had that file in my GPX Route folder. What happened: I imported single listed routes by highlighting all the files in my GPX Route folder. However I didn't notice the gpx file which had a group of routes contained in it. Once I removed the gpx file with a group of files, the import gpx worked as anticipated.

The GUID box is not useful for anything but knowing the GUID. Knowing the GUID is good to be able to find a specific object in OpenCPN's GPX data when processed in a text editor. Doing things with OpenCPN's GPX data in a text editor is something you normally don't do, but when you do, you are most happy that you know the GUID of a certain object.

Enable thw WMM World Magnetic Model please.

It makes no sense to use magnetic on true north facing mercator projections.

Ownship true north heading predictor is only displayed if true north value is available.

If HDT is not available in the nmea data stream we use HDM and variation from the WMM plugin to estimate an effective HDT.

Best to analyse the data stream with the individual xxGSV sentences etc. to understand the issue better.

Physical Changes

• Swinging Carbon fiber boom, electronic RFI.

AIS is not involved

• Use the NMEA debug window to check what's coming in to OCPN. If you device is sending individual sentences for each GNSS system, see the copied text below. You can filter out one at the time in OCPN connection properties. If your device is already combining different systems position to one GNxxx there's not much to do in OCPN more than check you've the Options→Display→Advanced→ “Chart rotation averaging time” set to at least 15 sec.
• “According to the NMEA 0183 protocol, the Talker ID serves to define the navigation system(s) used for the reported position coordinates. If only GPS, GLONASS, GALILEO etc. are used for the reported position solution the Talker ID is GP, GL, GA etc. and the errors pertain to the individual system. If satellites from multiple systems are used to obtain the reported position solution, the Talker ID is GN and the errors pertain to the combined solution. ”

GPS AIVDO Boat Position is Jumping many miles away.

• See this entire thread. http://www.cruisersforum.com/forums/f134/opencpn-jumping-map-194531.html#post2535508[93] You will need to use OpenCPN NmeaData Window and a Free nmea decoders[94] and a program like Notepad++ to figure out what the offending sentences are.
• Remember that “The NMEA standard uses two primary sentences to for AIS data !AIVDM (Received Data from other vessels) and !AIVDO (Your own vessels information)” AIS - Automatic Identification System - Information[95]
• Problem may be from having two different Own Ship position signals at the same priority, with the additional problem that AIVDO sentences position, sog & cog are just wrong. 1. First disable all but one GPS signal. (Disconnect or turn off.) 2. Stop sending AIVDO (Use either hardware or software settings.) 3. Filter out all AIVDO messages completely. See the User Manual > Connections > Filters[96] put “AIVDO” in the Input filtering line.

Chart Rotation Smoothing. When follow ship, offset mode, look ahead mode and north up mode are all turned on, the goal of the look ahead is to position the ship about 2/3 away from the farthest point directly ahead of the ship. Because the screen is a rectangle, the ship's position on the screen keeps changing, since the farthest point ahead is changing rapidly. Use Options > Display > Advanced Chart Rotation Averaging Time [new title] or Course-up Update Period _Time [old title] to smooth the chart rotation. It is actually another “always on” COG filter that smooths VP rotation and makes the chart much less jumpy. In conjunction with NMEA course and speed filtering the chart moves slowly in a nice way. Chart rotation averaging time” set to at least 15 sec.

• Under Options > Display > Advanced see Chart Rotation Averaging Time[97]
• and for more about Display Orientation -Look Ahead and Course up[98]

Disable Options > Connections > “Output this port (as autopilot or NMEA repeater)”, particularly if it is doing nothing. Once I unchecked the issue goes away.

The scale jumps appear very large. I have looked but cannot find a pref or other setting. It may be due to the scales of raster charts.

• Is it a driver problem? Does this happen in other programs.
• Is the battery low?
• Options > Display, check “Smooth Pan/Zooming”. It helps make zooming and panning much more controllable.
• Options > Display, check “Preserve scale when switching charts”.

How do I adjust scale factor for Ship and AIS, Chart Objects and the User Interface? Adjust the Three Scale Factors[99] Adjust how large the User Interface is. Adjust how large Ships and AIS symbols are. Adjust how large Chart Objects and vector depth sounding are.

Solution: Set the AIS targets to be shown scaled, in Settings > User Interface and near the bottom are sliders for scaling items. Use ship scale at 2 or 3 gets a nice sized AIS target. The Scale sliders were added for greater user control in the new version.

Tried the following:

1. Check setting Tools→Display→Advanced→Physical screen width. If not already Auto select that and Apply. Now read the mm value and compare to your screen width. If it does not conform, change to “manual” and enter your actual size.
2. Changing options such as “Ship icon type” and can get the ship icon back to readable size by changing the option from default to Real Scale Bitmap and setting the mm size to 30 but this does not change the AIS target size.
3. Checked setting for “Physical screen width”. Tools→Display→Advanced→Physical screen width. If not already “Auto” select that and “Apply”. Now read the mm value and compare to your screen width. If it not conform change to “manual” and enter your actual size.
4. Show AIS targets as real size does not help.
5. Note: The external monitor can be forced to display the correct sized icons by first enabling both the laptop display and the external monitor and then disabling the laptop display.
6. Also check Settings→Display→Advanced→Physical screen width. Does it match your actual device screen width in mm? When set to “Auto” the default Icon sizes should be reasonable when the Scale sliders are set to around 5 (midrange). See Settings > User Interface and the three Scale Sliders at the bottom here Adjust the Three Scale Factors[100]

OpenCPN requires a valid ownship GPS location to calculate range and bearing to AIS targets. It was not designed for stationary operation to monitor live AIS traffic without GPS input.

If you insist, you may use VDR plugin[101], by running a text file with a single GPRMC nmea sentence[102] describing your homebase location, repeated over and over….this will work, try this in a text file:

$GPRMC,180000.000,A,4221.0000,N,07106.0000,W,0.00,180.00,101017,,,*3E<cr><lf>

The TRUE Heading reported in the target query is always as actually reported by the target. We do not apply variation to that value before presentation. So, what you see is no error. Of course, in situations with strong cross currents, or maneuvering, the reported HDG and COG may be wildly different.

MOB SART has been tested extensively. The methods for deactivation should work. See SART[103]. Also Disable SART[104] When Alert is active, find the Alert's MMSI number in the AIS Target List. Then Add a “New” MMSI number in Options→Ships→MMSI. Then Edit the Options→Ships→MMSI Properties to “ignore” this target. Then close the Options Dialog. Then “Acknowledge” the SART alert one more time, and no further alerts will be seen. If you restart OCPN, you will never get alerts for this target again.

=== How can an AIS alert be disabled, blocked or ignored?

• Disable all AIS alerts by unchecking the global setting for “Show AIS alerts”
• Permanently Block a particular AIS alert as in Sart above, copy the MMSI number and once added to the Options>Ship>MMSI Tab, pick “Follow” in the MMSI Tab.

The file aids with faster display of vessel name, until first static information message is received from that vessel, which then overrides the cached value. Usually found in your user folder, for Windows C:/program files (x86)/programdate/opencpn/ Please see the AIS section under mmsiname CSV[105]

Yes, unless you break it. As it is created automatically, it is also safe to delete it. Please see Cruiser Forum post by Nohal[106] for more answers.

There are so many GPS models that the answer is a bit complicated. A lot depends on which GPS model you have. OpenCPN can communicate with many GPS receivers via a serial connection. Some GPS receivers have a serial connector that can be wired to a DB-9 serial connector. Newer ones have a USB port that will appear like a serial connection to your computer. Still newer ones appear to your computer like an external drive.

If your GPS receiver shows up as a serial connection on your computer chances are you can upload routes and waypoints directly to it from within OpenCPN. The GPS and OpenCPN have to be set to the same communication protocol. If you normally have them set to NMEA (for updating the OpenCPN chart display with position data from the GPS) you may need to change a Garmin GPS to the GRMN proprietary protocol to upload routes, waypoints, and tracks. If your GPS doesn't show up as a serial connection you may still be able to transfer routes and waypoints to it outside of OpenCPN. If the GPS appears as an external drive on your computer try this. Use OpenCPN to export your routes and waypoints to a GPX file (read the User Manual section on the Route & Mark Manager for more details). Then use your operating system to copy the GPX file from your hard drive to your GPS. If that doesn't work, try GPSBabel or EasyGPS for the transfer.

Depending on your GPS model and the way the route was created in OpenCPN you may wind up with a route on your GPS or just a list of waypoints. The route points may or may not appear as waypoints on the GPS.

• Garmin has a program called Homeport which connects to most of their small GPSmap and Plotters which will upload/download waypoints and routes. I believe it will also import gpx routes.
• EasyGPS[107] is a free program that allows you to transfer routes, waypoints, and tracks between your Windows computer and your Garmin, Magellan, or Lowrance GPS.
• GPSBabel[108] is another free program that allows you to transfer data between your computer and your GPS. It runs on Windows, Mac, and Linux operating systems and supports a wide range of GPS models.
• There are also some helpful notes in the manual.
• Route & Mark Manager[109]
• Sending Routes and Waypoints to a GPS[110]
• Hardware GPS Devices[111]
• The oBabel plugin uses GPSBabel to transfer routes without leaving OpenCPN.

• In Windows, Night, F5, mode. The title bar on the floating plugin window is a bit glaring (this mode is controlled by windows by way of a theme and is not possible to change from an application) .
• The best solution is to simply “dock” the dashboard window at night, either left or right. This brings the window decorations back under OCPN control, and we recently added logic to dim it in this mode.
• Dimming the screen, if it is available and goes far enough is often best. F6 General Dimming, in steps, of the entire Screen. (except Mac OS X ). OpenGL must be off.
• Otherwise the “Change color scheme' F5 button or (C, Ctrl+C, Ctrl+G). This may or may not work on your particular computer.
• See Keyboard Shortcuts[112]
• For Linux users, who have little differentiation between shallow water colurs and land colours, try “F.Lux” which has a 2000k setting that makes the screen quite dull over the daytime colour palette. F.lux is confirmed as massive win on Linux. Daytime palette and use F7 to drop the brightness a bit more if needed. https://itsfoss.com/night-shift-flux-ubuntu-linux/[113]

• See Options > User Interface[114] Fonts and Font Color.

• Close Opencpn.
• In the Opencpn.ini or opencpn.conf file find DefaultFontSize=0 under the [Settings] section, just below ShowMenuBar=0
• Change the defaultfontsize setting to the font size you would like use and save the file.
• Load Opencpn and check your font sizes.

• The AIS Target List does not exist in UI > Options Fonts selection. AIS target list uses the “Dialog” font key in Options > User Interface, Fonts and Font Color..

Out of the box, the “Depth” notation is unreadable.

• Try Options > User Interface > Chart Object Scale Slider set on +4 or +5.
• Try using the Swedish color palette[115] which changes depth font to black.
• The Chart Object Scale Slider is for Vector Charts only.
• Raster Chart cartography is superior and depths are very clear in comparision.

1. Opening the properties page, and adding a link to a JPG-image works fine. If I now edit the link, the image will no longer be displayed.
   1. The button “Edit” changes state. You click on it to switch the links above to “edit mode”, each click on any of the links opens the dialog allowing you to change it's parameters. After editing the link, you have to click on the button again and then a click on the links will again start opening whatever they link to. What will happen when you click on the link is explained in the text below the buttons and changes according to the “Edit button”. If it says “Links are opened in the default browser”, the linked file or internet address should open, given it exists, which gets us to..
2. Similarily, if I export a waypoint with a link to another computer, the link will not open.
   1. The link is just a link, the file you link to is NOT “included” in the waypoint. When you transfer the waypoints to another computer, for links to local files to keep working, the files you link to would have to exist on the exactly same place on your disk there. Eg. The file that on computer A is C:\MyDocuments\MyPicture.jpg would have to exist with exactly the same file name, in the exactly same folder, on the exactly same disk on computer B.

1. There is a Route Plugin for Great Circles.
2. Raster charts display bearings and headings as straight, measurable lines on the chart. Similarly, Vector ENC's are rendered as Mercator projections in OpenCPN and most other ECS's for the same reason.
3. For typical coastal navigation, errors which occur using rhumb line instead of great circle calculations are small for the distances usually covered by one chart.
4. Mercator Charts and Mercator navigation is the standard for most navigational purposes. Other terms used instead of “Mercator Sailing” is “Loxodrome Sailing” or “Rhumb Line Sailing”.

• Great Circle Routes are explained Great Circle Sailing[116].
• There is also a plugin available as well as some Supplementary Software[117] to handle great Circles.

'Enable Touchscreen interface' in Options/User Interface disables the rollover feature on my PC with a touchscreen. With this setting enabled, touching a target displays the target information. Without it enabled the rollover feature works.

“Rollover” is a mouse thing. One does not exactly “rollover” with a touchscreen. This could get very distracting to the overall UI. Thus, rollover is disabled for touch.

1. Start OCPN. Set the toolbar as you would like it. No dashboard visible yet.
2. Grab a screenshot.
3. Exit OCPN cleanly by closing the Opencpn window normally. Restart and the settings should be saved.
4. Using the Raspberry Pi shutdown, top left corner, select shutdown, is wrong, like instant stop.
5. See Forum Thread[118]

Issue just started with 4.8.0 where on exit doesn't save * Units * Configuration of toolbar * Starts in night mode I searched the opencpn.ini for these settings but not sure what I am looking for TBH. I also backed up this file and exited the program forming a new ini file, same issue. Any ideas?

OpenCPN is probably set to use settings for Inland ECDIS European Inland Waterways ECDIS

• Click the wrench (or spanner) icon on toolbar to open the “Settings” dialog.
• Select the “User Interface” tab, and
• look below the “Interface Options” for
• “Use Settings for Inland ECDIS Version 2.3”.
• Remove the checkmark on the “Use … Inland ECDIS…” line.

The new Active Route always disappears and I try to recreate it and it disappears again.

• If the distance to waypoint increases slightly then route manager says we have “arrived” and it tries to advance to the next waypoint.
• But in a simple “Navigate to here” scenario there is no next waypoint so it just assumes it has arrived at the destination.
• Also this problem may be due to some “noise” from the GPS position.
• Try setting Options > Ships > Own Ship in the Routes box check “Advance route waypoint on arrival only”.

If HDG message also contains the variation and E/W flags then O will use that. If not then it will look in RMC message for a variation. If nothing there it will use WMM plugin unless user has selected the variation manually in options.

Question: Layers is a good feature, however I need a tool to create a layer with many waypoints (say 200 waypoints in Fiji). I'd like create a layer of all visible waypoints in a chart area that I have zoomed into. After creating the layer, I'd like to delete them from the waypoints list with a single command.

Answer: Using the Route & Mark Manager[119]

• Import the waypoints into the Waypoints Tab[120].
• Select all the Waypoints by clicking & highlight the top waypoint, scroll to the bottom and while holding the Shift key, click to highlight all.
• Wait for all the waypoints to be highlighted.
• Click on the button “Export selected …”.
• Browse to choose the directory to save the waypoints, & name the file 'Fiji Waypoints'.
• Click on 'Save'.
• All the waypoints will be in one .gpx file which, when put in the Layers folder can be displayed or not in the Layers Tab[121] by toggling the 'eyeball'.
• You can also use the 'List contents' in the Layers Tab to have the Waypoints displayed in the Waypoints Tab.
• When done you can clear the Waypoints Tab from the Layers tab by clicking on 'Unlist Contents'.
• See Handling Layers[122]

1. Mark the routes in the Route&Mark Manager, recording the order.
2. Then export each route as a gpx file.
3. Open the first file in a text editor.
4. Open the next file in the text editor and copy the code between <rte> … </rte> not including them.
5. Then paste the code directly before the </rte> at the end of the first file.
6. Continue until done. Save the first file.
7. Import the gpx file with a new name.

Distorted sound

• Unordered List ItemThe wav file MUST be 16 bit, mono 22050 Hz in order to play correctly. I've converted the sounds from mp3 to wav using:

mpg123 -2 -m -w out.wav in.mp3 This is on a Raspberry PI using OpenPlotter 1.1.0 alpha) 

No Sound in RPI:

• Disable the onboard audio in /boot/config.txt, edit files /usr/share/alsa/alsa.conf and /etc/asound.conf to point to card 1 (my USB speaker as shown in response to “aplay -l”.
• Change Tools > Options > User Interface > Sound Device Index to 1 and the result is Watchdog and AIS test alarms work fine.

RPI 3B+ is running now for several hours with OpenCPN and chart open. No more locks ups or screen errors. VC4 driver on and in OpenCPN also OpenGL to on. Fast screen movements. Something seems to go wrong with the auto screen detection in OpenCPN. Use manual screen settings to set the proper display size. Back to kernel 4.14.62 ( 4.14.68 kernel and 4.14.69 and 67 seems to have also a memory leak) the system is runs all day without problems and with OpenGL switched on. Screen is an DVI with a conversion plug DVI > HDMI.

Going to Toolbar/Options/Plugins/Grib 4.1/Preferences; OpenCPN freezes when you check “Authorize interpolation to start at current time” (a warning first followed by a freeze requiring a “Force Quit” of the application).

• It is not frozen, but the active modal window with the preferences sinks below the other windows as the information message dialog is displayed. Cmd-Tab to switch to another application followed by another Cmd-Tab to switch back to OpenCPN should bring it back on top (Or an Esc acts as Cancel). Certainly to be fixed with all the other z-order issues on macOS.

Set time to local for weather routing in view→settings. Set time to local for grib_pi in preferences.

A user can install his or her own icons to use with marks and “own ship”. See Install your own Icons[123] “To replace the default own ship icon, red ship icon just put a file “ownship.xpm” or “ownship.png” in the UserIcons directory.”

If you are using WindowsXP, it will not appear because WinXP does not support the encryption requiired. Sorry.